
from typing import List
class Solution:
    def nextPermutation(self, nums: List[int]) -> None:
        i = len(nums) -2
        while i>=0 and nums[i] >= nums[i+1]:
            i-=1
        if  i>=0:
            j = len(nums)-1
            while j>=0 and nums[i] >= nums[j]:
                j-=1
            nums[i],nums[j] = nums[j],nums[i]
        left,right = i+1,len(nums)-1
        while left < right:
            nums[left],nums[right] = nums[right],nums[left]
            left+=1
            right-=1
        return nums